MAGNESIUM Overview Information

Magnesium is a mineral that is present in relatively large amounts in the body. Researchers estimate that the average person’s body contains about 25 grams of magnesium, and about half of that is in the bones. Magnesium is important in more than 300 chemical reactions that keep the body working properly. People get magnesium from their diet, but sometimes magnesium supplements are needed if magnesium levels are too low. Dietary intake of magnesium may be low, particularly among women.

An easy way to remember foods that are good magnesium sources is to think fiber. Foods that are high in fiber are generally high in magnesium. Dietary sources of magnesium include legumes, whole grains, vegetables (especially broccoli, squash, and green leafy vegetables), seeds, and nuts (especially almonds). Other sources include dairy products, meats, chocolate, and coffee. Water with a high mineral content, or “hard” water, is also a source of magnesium.

People take magnesium to prevent or treat magnesium deficiency. Magnesium deficiency is not uncommon in the US. It’s particularly common among African Americans and the elderly.

Magnesium is also used as a laxative for constipation and for preparation of the bowel for surgical or diagnostic procedures. It is also used as an antacid for acid indigestion.

Some people put magnesium on their skin to treat infected skin ulcers, boils, and carbuncles; and to speed up wound healing. Magnesium is also used as a cold compress in the treatment of a severe skin infection caused by strep bacteria (erysipelas) and as a hot compress for deep-seated skin infections.

Some companies that manufacturer magnesium/calcium combination supplements promote a 2:1 or 3:1 ratio as being ideal for absorption of these elements. However, there is no credible research to support this claim. Claims that coral calcium products have ideal combinations of magnesium and calcium to cure a variety of diseases and conditions are being carefully evaluated by the US Food and Drug Administration (FDA) and US Federal Trade Commission (FTC).

How does it work?

Magnesium is required for the proper growth and maintenance of bones. Magnesium is also required for the proper function of nerves, muscles, and many other parts of the body. In the stomach, magnesium helps neutralize stomach acid and moves stools through the intestine.

MAGNESIUM Uses & Effectiveness

Constipation. Taking magnesium by mouth is helpful as a laxative for constipation and to prepare the bowel for medical procedures.

Dyspepsia (heartburn or “sour stomach”). Taking magnesium by mouth as an antacid reduces symptoms of heartburn. Various magnesium compounds can be used, but magnesium hydroxide seems to work the fastest.

Magnesium deficiency. Taking magnesium is helpful for treating and preventing magnesium deficiency. Magnesium deficiency usually occurs when people have liver disorders, heart failure, vomiting or diarrhea, kidney dysfunction, and other conditions.

High blood pressure during pregnancy (pre-eclampsia and eclampsia). Administering magnesium intravenously (by IV) or as a shot is considered the treatment of choice for reducing high blood pressure during pregnancy (pre-eclampsia) and for treating eclampsia, which includes the development of seizures. Research suggests that administering magnesium reduces the risk of seizures.

Asthma. Giving magnesium intravenously (by IV) seems to help treat sudden asthma attacks. However, it might be more beneficial in children than in adults. Taking magnesium by mouth does not seem to improve attacks in people with long-term asthma.

Diabetes. Eating a diet with more magnesium is linked with a reduced risk of developing diabetes in adults and overweight children. Research on the effects of magnesium for people with existing diabetes shows conflicting results.

Hearing loss. Taking magnesium by mouth seems to prevent hearing loss in people exposed to loud noise. Also, taking magnesium seems to improve hearing loss in people with sudden hearing loss not related to loud noise.

High cholesterol. Taking magnesium chloride and magnesium oxide appears to slightly decrease low-density lipoprotein (LDL or “bad”) and total cholesterol levels, and slightly increase in high-density lipoprotein (HDL or “good”) cholesterol levels in people with high cholesterol.

Metabolic syndrome (increased risk for diabetes and heart disease). People with low magnesium levels are 6-7 times more likely to have metabolic syndrome than people with normal magnesium levels. Higher magnesium intake from diet and supplements is linked with a lower risk of developing metabolic syndrome in healthy women and healthy young adults.

Migraine headaches. Taking high doses of magnesium by mouth seems to reduce the frequency and intensity of migraine headaches in some studies. However, other research suggests that it does not have any effect. It may be that only people with low levels of magnesium respond to treatment.

Diseases of heart valves (mitral valve prolapse). Taking magnesium seems to reduce symptoms of mitral valve prolapse in people with low magnesium levels in their blood.

Pain after a hysterectomy. Giving magnesium intravenously (by IV) seems to be help reduce pain after a surgical procedure to remove the uterus called a hysterectomy. There is some evidence that a high magnesium dose of 3 grams followed by 500 mg per hour can reduce discomfort. However, lower doses do not seem to be effective and might actually increase pain.

Pain after surgery. When administered with anesthesia or given to people after surgery, magnesium seems to increase the amount of time before pain develops after surgery.

Stroke. Consuming more magnesium in the diet might decrease the risk of stroke in men. There is no proof that taking magnesium supplements has this same effect.

Chest pain due to blood vessel spasms (vasospastic angina). Giving magnesium intravenously (by IV) seems to prevent blood vessel spasms in people with chest pain caused by spasms in the artery that supplies blood to the heart.

Heart attack. In general, giving magnesium intravenously (by IV) or taking magnesium by mouth does not seem to reduce the overall risk of death after a heart attack.

Athletic performance. Taking magnesium by mouth does not seem to increase energy or endurance during athletic activity

Muscle cramps. Taking magnesium supplements does not seem to decrease the frequency or intensity of muscle cramps.

Stillbirths. Taking magnesium supplements during pregnancy does not seem to decrease the risk of stillbirths.

Tetanus. Taking magnesium does not seem to reduce the risk of death in people with tetanus compared to standard treatment. However, taking magnesium might reduce the amount of time spent in the hospital, although results are conflicting.

Traumatic brain injury. Taking magnesium does not seem to improve brain damage or reduce the risk of death in people with a traumatic brain injury.

Alcohol withdrawal. Taking magnesium by mouth seems to improve sleep quality in people who are dependent on alcohol and going through withdrawal. However, injecting magnesium as a shot does not seem to reduce alcohol withdrawal symptoms.

Altitude sickness. Taking magnesium before climbing a mountain and continuing until descending the mountain does not seem to prevent altitude sickness.

Aluminum phosphide poisoning. Some research suggests that taking magnesium reduces the risk of death in people with aluminum phosphide poisoning. Other research suggests magnesium does not have this effect.

Anxiety. Early research suggests that taking magnesium, hawthorn, and California poppy (Sympathyl, not available in the U.S.) might help treat mild to moderate anxiety disorder.

Attention deficit-hyperactivity disorder (ADHD). Children with ADHD seem to have lower magnesium levels. Early research suggests that magnesium might help treat ADHD in children with low magnesium levels.

Bipolar disorder. Early research suggests that taking a certain magnesium product (Magnesiocard) may have similar effects as lithium in people with bipolar disorder.

High blood pressure. Some research suggests that taking magnesium slightly reduces diastolic blood pressure (the bottom number in a blood pressure reading) in people with mild to moderate high blood pressure. Magnesium might not lower systolic blood pressure (the top number in a blood pressure reading).

Kidney stones. Taking magnesium by mouth might prevent the recurrence of kidney stones, but other medications such as chlorthalidone (Hygroton) may be more effective.

Mania. Early research suggests that taking magnesium plus the drug verapamil reduces manic symptoms better than just verapamil alone. Other early research suggests that giving magnesium intravenously (by IV) reduces the dose of other drugs needed to manage severe mania symptoms.

Pregnancy-related leg cramps. Research on the use of magnesium for treating leg cramps caused by pregnancy has been inconsistent. Some studies show that magnesium might reduce leg cramps during pregnancy. However, another study shows no benefit.

Premature labor. Giving magnesium intravenously (by IV) might prevent contractions when premature labor occurs. Some research suggests that magnesium is more effective at delaying labor by 48 hours compared to some conventional drugs. However, not all experts believe it is beneficial, and some research suggests it is not more effective than conventional drugs.

Restless leg syndrome. Taking magnesium might decrease the amount of movement and increase the amount of sleep in patients with restless leg syndrome. However, the role of magnesium, if any, in restless leg syndrome is uncertain. Some people with this condition have high levels of magnesium in their blood, while others have low magnesium levels.

Bleeding in the brain (subarachnoid hemorrhage). There is mixed evidence on the effect of magnesium in managing bleeding in the brain. Some research suggests that giving magnesium intravenously (by IV) reduces the risk of death and vegetative state. However, other research does not support these findings.

Sudden cardiac death. Some preliminary research suggests that higher levels of magnesium are linked with a lower chance of experiencing sudden cardiac death. However, it is not known if taking a magnesium supplement reduces the risk of sudden cardiac death. Giving magnesium intravenously does not seem to have a benefit.

Hayfever.

Lyme disease.

Other conditions.

More evidence is needed to rate magnesium for these uses.

MAGNESIUM Side Effects & Safety

Magnesium is LIKELY SAFE for most people when taken by mouth appropriately or when the prescription-only, injectable product is used correctly. In some people, magnesium might cause stomach upset, nausea, vomiting, diarrhea, and other side effects.

Doses less than 350 mg per day are safe for most adults. When taken in very large amounts, magnesium is POSSIBLY UNSAFE. Large doses might cause too much magnesium to build up in the body, causing serious side effects including an irregular heartbeat, low blood pressure, confusion, slowed breathing, coma, and death.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Magnesium is LIKELY SAFE for pregnant or breast-feeding women when taken by mouth in the recommended amounts. These amounts depend on the age of the woman. Check with your healthcare provider to find out what amounts are right for you.

Bleeding disorders: Magnesium seem to slow blood clotting. In theory, taking magnesium might increase the risk of bleeding or bruising in people with bleeding disorders.

Heart block: High doses of magnesium (typically delivered by IV) should not be given to people with heart block.

Kidney problems, such as kidney failure: Kidneys that don’t work well have trouble clearing magnesium from the body. Taking extra magnesium can cause magnesium to build up to dangerous levels. Don’t take magnesium if you have kidney problems.

MAGNESIUM Interactions

Some antibiotics can affect the muscles. These antibiotics are called aminoglycosides. Magnesium can also affect the muscles. Taking these antibiotics and getting a magnesium shot might cause muscle problems.
Some aminoglycoside antibiotics include amikacin (Amikin), gentamicin (Garamycin), kanamycin (Kantrex), streptomycin, tobramycin (Nebcin), and others.

Antibiotics (Quinolone antibiotics) interacts with MAGNESIUM

Magnesium might decrease how much antibiotic the body absorbs. Taking magnesium along with some antibiotics might decrease the effectiveness of some antibiotics. To avoid this interaction take these antibiotics at least 2 hours before, or 4 to 6 hours after, magnesium supplements.
Some of these antibiotics that might interact with magnesium include ciprofloxacin (Cipro), enoxacin (Penetrex), norfloxacin (Chibroxin, Noroxin), sparfloxacin (Zagam), trovafloxacin (Trovan), and grepafloxacin (Raxar).

Antibiotics (Tetracycline antibiotics) interacts with MAGNESIUM

Magnesium can attach to tetracyclines in the stomach. This decreases the amount of tetracyclines that the body can absorb. Taking magnesium along with tetracyclines might decrease the effectiveness of tetracyclines. To avoid this interaction take calcium 2 hours before or 4 hours after taking tetracyclines.
Some tetracyclines include demeclocycline (Declomycin), minocycline (Minocin), and tetracycline (Achromycin).

Bisphosphonates interacts with MAGNESIUM

Magnesium can decrease how much bisphosphate the body absorbs. Taking magnesium along with bisphosphates can decrease the effectiveness of bisphosphate. To avoid this interaction take bisphosphonate at least two hours before magnesium or later in the day.
Some bisphosphonates include alendronate (Fosamax), etidronate (Didronel), risedronate (Actonel), tiludronate (Skelid), and others.

Some "water pills" can increase magnesium levels in the body. Taking some "water pills" along with magnesium might cause too much magnesium to be in the body.
Some "water pills" that increase magnesium in the body include amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium).

The daily Recommended Dietary Allowances (RDA) for elemental magnesium are: Age 1-3 years, 80 mg; 4-8 years, 130 mg; 9-13 years, 240 mg; 14-18 years, 410 mg (boys) and 360 mg (girls); 19-30 years, 400 mg (men) and 310 mg (women); 31 years and older, 420 mg (men) and 320 mg (women). For pregnant women age 14-18 years, the RDA is 400 mg; 19-30 years, 350 mg; 31-50 years, 360 mg. For lactating women age 14-18 years, the RDA is 360 mg; 19-30 years, 310 mg; 31-50 years, 320 mg. For infants less than one year of age, adequate intake (AI) levels are 30 mg from birth to 6 months and 75 mg from 7 to 12 months. The daily upper intake level (UL) for magnesium is 65 mg for children age 1-3 years, 110 mg for 4-8 years, and 350 mg for anyone over 8 years old, including pregnant and breast-feeding women.

Ziegelstein RC, Hilbe JM, French WJ, et al. Magnesium use in the treatment of acute myocardial infarction in the United States (observations from the Second National Registry of Myocardial Infarction). Am J Cardiol 2001;87:7-10.. View abstract.

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